The Kuang Si Falls, sometimes spelled Kuang Xi, is a three tier waterfall about 29 kilometres (18 mi) south of Luang Prabang in Laos. The falls begin in shallow pools atop a steep hillside. These lead to the main fall with a 50 m cascade. The water collects in numerous turquoise blue pools as it flows downstream. The many cascades that result are typical of travertine waterfalls.

It is well main maintained with walkways and bridges to guide the visitor. Most of the pools are open to swimming (although at least one is closed as being a sacred site). Hikers are able to climb to the top of the falls.